ENOfficial
It was narrated that Thawban said: “The Messenger of Allah (ﷺ) said: ‘No person should lead others in prayer, then supplicate only for himself and not for them. If he does that, he has betrayed them.’”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُصَفَّى الْحِمْصِيُّ، حَدَّثَنَا بَقِيَّةُ بْنُ الْوَلِيدِ، عَنْ حَبِيبِ بْنِ صَالِحٍ، عَنْ يَزِيدَ بْنِ شُرَيْحٍ، عَنْ أَبِي حَىٍّ الْمُؤَذِّنِ، عَنْ ثَوْبَانَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " لاَ يَؤُمُّ عَبْدٌ فَيَخُصَّ نَفْسَهُ بِدَعْوَةٍ دُونَهُمْ فَإِنْ فَعَلَ فَقَدْ خَانَهُمْ " .
sunnah.com